Many computing platforms utilize expansion bus architectures for connecting host devices (e.g., processors and memories) to input-output (I/O) devices. For example, expansion bus architectures may be used in end user computers to connect processors and memories to various computer peripheral devices (e.g., network interface cards (NICs), storage devices, sound cards, graphics processors, or the like). Similarly, expansion bus architectures may be used in network elements, such as servers and switches, to connect processors and memories to various network element I/O devices (e.g., line cards, server blades of multi-node enclosures, fabric switch blades of multi-tray enclosures, storage devices, controllers, or the like). However, flexible computing platforms having flexible expansion bus architectures are generally difficult and expensive to both design and implement.